GB191322A - Improvements in and relating to foot-operated air-pumps for pneumatic tyres, and the like - Google Patents

Abstract

191,322. Lumby, V. April 3, 1922. Oscillating -cylinder pumps; actuating pumps by foot power.-Oscillating cylinder pumps, in which two frame members such as a, b are hinged together as at c and normally separated by a spring, and in which a cylinder such as k is pivoted to one member and a piston such as g is pivoted to the other member, are modified to secure ready folding of the parts for storage without moving the pivot, pins bodily in slots or the like in the frame members. The trunnions q of the cylinder become coaxial with the piston pivots h when the frame members are closed, so that the piston and cylinder can be folded to lie against the folded frame. One part of the lower edge of the cylinder is cut away at p to pass the lugs during the folding action. In some cases this cut away portion may be arranged to engage the nut on the piston pivot pin to keep the cylinder and frame in the folded position. The piston and cylinder, when folded, are not under the influence of any spring pressure that would make the piston press against one side of the cylinder and thus make the cup leather wear unequally. A pivoted catch t may lock the frame members in the closed position. Clearance is provided between the cylinder walls and the frame b, and the intervening space is filled by springs coiled round the trunnions q. Preferably the trunnions are mounted in depending portions of the frame which enter recesses r<1> in the other frame when the appliance is folded.